MEDULLA OBLOXGATA. 409 



the so-called vital point. 1 As regards the experiments upon 

 which the opinion of Brown-Sequard is based, we have only 

 to say that, while a return of respiratory movements is per- 

 haps possible in certain cold-blooded animals (which will live 

 for weeks after extirpation of the medulla, respiring by the 

 skin alone) the experiments on rabbits are so extraordinary, 

 and the results obtained are so diametrically opposed to 

 those of all other observers, that they cannot be accepted 

 without full confirmation. As is remarked by Yulpian, if 

 the cause of arrest of respiration in the higher animals were 

 due, not to removal of the respiratory centre, but to simple 

 irritation, these movements should return after the circula- 

 tion had been kept up for a time by artificial respiration. 

 This never occurs. " The possibility of reflex movements 

 remains during all the time of pulmonary insufflation ; but 

 the respiratory movements are definitively abolished." 3 We 

 must then adhere to the view that the medulla oblongata is 

 the centre which presides over the respiratory movements. 



To conclude our history of the influence of the medulla 

 on respiration, we have only to refer to an interesting series 

 of experiments recently made by Schiff, in which one lateral 

 half of the cord just below the medulla, or the lowest part 

 of the medulla, was divided. In these experiments, it was 

 found that section of the lateral columns at the point of ori- 

 gin of the first pair of cervical nerves abolished respiratory 

 movements upon the corresponding side of the body. In 

 one experiment, the section was made in a dog, and all the 

 movements, except those of respiration, remained. The ab- 

 domen was opened, and one-half of the diaphragm was seen 

 to be entirely passive. In another experiment, exposure of 

 the diaphragm did not affect the volume of air inspired, but 

 after section of the lateral column on one side, the volume 

 of air inspired was diminished by about one-third. 3 



1 SCHIFF, Lehrbuch der Physiologic, Lahr, 1858-'59, S. 323. 



2 VULPIAN, Systeme ncrveux, Paris, 1866, p. 507. 



8 SCHIFF, Einfluss des verlangerten Marks auf die Athmung. Archiv fur die 

 ytsammte Physiologic, Bonn, 1870, Bd. iiL, S. 624. 



